That's the properly part. If you make a form and the output is supposed to go in a particular place and it doesn't (hx-swap), then it isn't functioning properly. The degree to which it is improperly functioning depends on the UI and the user. In many cases it's improperly enough that it may as well either work or not work.
As mentioned, htmx will attach a `HX-Request: true` header to the request[1]. The server can check this header and either return a partial for swapping, or a full page/redirect like in good old days. Same with any request. This is one way of how htmx provides "progressive enhancement". Sure, this may not be as transparent, as other JS-first frameworks implement it, but it's not complex at all.
The only thing that might cause trouble is non-standard (as in HTML standard) HTTP methods, which basically means any method other than GET and POST, I admit that. However, the fact that these methods are not supported even in HTML5 is a huge miss.
